| 摘要 |
PURPOSE:To contrive an improvement in yield and a reduction in cost by irradiating one of waveguides with a CO2 laser beam. CONSTITUTION:One of two pieces of the single mode waveguides 4, 5 in proximity to each other is irradiated with the CO2 laser 1 and is thereby corrected in dividing characteristics at the time of the constituting a waveguide type Mach-Zehnder interferometer by connecting the two directional couplers constituted of the above-mentioned waveguides 4, 5 in series, thereby producing the Mach-Zehnder type optical multiplexer/demultiplexer 3 having the difference DELTAL in the length between the two waveguides (a) and (b) between the two directional couplers satisfying equation I. In the equation I, lambda1, lambda2 denote the wavelength of the light to be spectrally divided, ng denotes the group refractive index of the waveguide (a) and the waveguide (b); DELTAlambda(=¦lambda1-lambda2¦) denote the wavelength intervals of the light to be spectrally divided. The control of the dividing characteristics of the Mach-Zehnder type optical multiplexer/ demultiplexer 3 is, therefore, possible. The dividing characteristics are corrected in this way and the tuning of the dividing characteristics is executed, by which the improvement in the yield and the reduction in cost are contrived. |
